update code:dfs&bfs of binary tree

Author: imoyao

Tree/Binary_tree/bintree_bfs_and_dfs.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Created by imoyao at 2019/10/28 18:15
+
+# https://blog.csdn.net/xinxin957_/article/details/81915443
+# https://blog.csdn.net/zzfightingy/article/details/86742755
+class Node:
+    """
+    定义Node类，用于表示树上的节点
+    """
+
+    def __init__(self, data, left_tree=None, right_tree=None):
+        """
+        节点值、左子树、右子树
+        :param data:
+        :param left_tree:
+        :param right_tree:
+        """
+        self.data = data
+        self.left_subtree = left_tree
+        self.right_subtree = right_tree
+
+
+class BinTree:
+    """
+    定义二叉树类
+    """
+
+    def __init__(self, root=None):
+        self.root = root
+
+    def add_node(self, val):
+        """
+        添加元素
+        :param val:
+        :return:
+        """
+        new_node = Node(val)
+        if self.root is None:
+            self.root = new_node
+        else:
+            queue = list()
+            queue.append(self.root)
+            while queue:
+                current = queue.pop(0)  # 从列表头部拿元素
+                if current.left_subtree is None:
+                    current.left_subtree = new_node
+                    return
+                elif current.right_subtree is None:
+                    current.right_subtree = new_node
+                    return
+                else:
+                    queue.append(current.left_subtree)
+                    queue.append(current.right_subtree)
+
+    def bfs_travel(self):
+        """
+        广度优先遍历
+        :return:
+        """
+        if self.root is None:
+            return
+        else:
+            queue = list()
+            queue.append(self.root)
+            while queue:
+                current = queue.pop(0)
+                print(current.data, end=' ')
+                if current.left_subtree is not None:
+                    queue.append(current.left_subtree)
+                if current.right_subtree is not None:
+                    queue.append(current.right_subtree)
+
+    def dfs_travel_preorder(self, node):
+        """
+        深度优先前序遍历（递归实现）
+        :param node:
+        :return:
+        """
+        if node is None:
+            return
+        else:
+            print(node.data, end=' ')
+            self.dfs_travel_preorder(node.left_subtree)
+            self.dfs_travel_preorder(node.right_subtree)
+
+    def dfs_travel_inorder(self, node):
+        """
+        深度优先中序遍历（递归实现）
+        :param node:
+        :return:
+        """
+        if node is None:
+            return
+        else:
+            self.dfs_travel_inorder(node.left_subtree)
+            print(node.data, end=' ')
+            self.dfs_travel_inorder(node.right_subtree)
+
+    def dfs_travel_postorder(self, node):
+        """
+        深度优先后序遍历（递归实现）
+        :param node:
+        :return:
+        """
+        if node is None:
+            return
+        else:
+            self.dfs_travel_postorder(node.left_subtree)
+            self.dfs_travel_postorder(node.right_subtree)
+            print(node.data, end=' ')
+
+
+if __name__ == '__main__':
+    t = BinTree()
+    for i in range(10):
+        t.add_node(1)
+    t.bfs_travel()
+    print('bfs_travel')
+    t.dfs_travel_preorder()